An armature. In the above magneto, the armature is shaped like a capital "U". The two ends of the U point toward the flywheel.
A primary coil of perhaps 200 turns of thick wire wrapped around one leg of the U
A secondary coil of perhaps 20,000 turns of very thin wire wrapped around the primary coil
A simple electronic control unit that commonly goes by the name "electronic ignition" (or a set of breaker points and a capacitor)
A pair of strong permanent magnets embedded in the engine's flywheel.
When the magnets fly past the U-shaped armature, they induce a magnetic field in the armature. This field induces some small amount of current in the primary and secondary coil. What we need, however, is extremely high voltage. Therefore, as the magnetic field in the armature reaches its maximum, a switch in the electronic control unit opens. This switch breaks the flow of current through the primary coil and causes a voltage spike (of perhaps 200 volts). The secondary coil, having 100 times more turns than the primary coil, amplifies this voltage to approximately 20,000 volts, and this voltage feeds to the spark plug.

Ok, question though. Why do I set it to 500 or 750 volts a/c when the reading I'm looking for is below 500 volts? Or is it set above the 448 reading because the multimeter will read UP to 500 or 750 volts? As in the range 0 > 750.

I'm just looking at multimeters now, to purchase one, I'm noticing some have 500, some have 750, some have neither!?

Ok, question though. Why do I set it to 500 or 750 volts a/c when the reading I'm looking for is below 500 volts? Or is it set above the 448 reading because the multimeter will read UP to 500 or 750 volts? As in the range 0 > 750.

I'm just looking at multimeters now, to purchase one, I'm noticing some have 500, some have 750, some have neither!?

Because if you set it at for example 200, you will not get a reading, because you want to measure higher voltage.
Think of it like this, you set the range for what you want to measure, 0V being lowest, whatever number you set it to being the highest. So when you set the voltmeter to 200Va\c, you set it up for measuring voltage within the range of 0V to 200V. When you set it to 750, you set up the voltmeter for measuring voltage within the range of 0V to 750V.